There has been known a technique for determining whether or not an operation is to be assisted on the basis of a sensing result of an operating state of an operation member fixed to a vehicle. For example, in Patent Literature 1 is disclosed to an operation assistance device a technique for outputting a state in which a winker relay operatively connected to the operation of a winker lever is energized or de-energized and for starting operation assistance when the operation assistance device determines that a turn signal lamp is on.